The current discussion is focused on a device to facilitate proper positioning of the sitting patient for epidural or spinal injection procedures, for example, to facilitate proper positioning of the pregnant patient in the sitting position for placement of an epidural and/or spinal anesthetic.
Epidural and/or spinal puncture or injection is a medical technique whereby therapeutic substances and catheters are introduced through a needle into the epidural or spinal spaces through the tissues of the back.
The procedure is most commonly performed in the lower (lumbar) spine by anesthesiologists in order to relieve pain in pregnant women laboring during childbirth. The procedure can also be used at other spinal levels and for such varied indications as to administer anesthesia for surgical procedures and to treat chronic pain conditions.
To perform epidural or spinal injection, the patient must first be positioned sitting on a standard hospital bed or other platform so that the anesthesiologist has access to the patient's back. The anesthesiologist can then place the epidural needle through skin and deep tissue layers in the back, between the bones of the spine, and into the epidural or spinal space as desired. Improper position or patient movement during this procedure can cause both technical difficulty in accomplishing the procedure, and injury to the patient.
Standard references in Anesthesiology (eg.: Benumof J. L. et al., Clinical Procedures in Anesthesia and Intensive Care. 1992 J.B. Lippincott Co, pg 655-656) recommend positioning the sitting patient for epidural or spinal anesthesia by having the patient sit ‘at the midpoint of the operating table with legs over the side edge, knees bent, and feet supported by a stool’ and having the patient ‘lean forward on an assistant or other suitable support.’.
The direction to ‘lean forward’ can actually be counterproductive to proper patient positioning. Most patients respond to the instruction to lean forward by flexing forward from the hips, rather than forward flexing the curve of their spine. This is particularly problematic in pregnant patients in labor, where the ability to forward flex the lumbar spine is reduced due to mechanical interference from the large size of the pregnant uterus.
Anesthesiologists use a variety of makeshift methods to position patients for sitting epidural or spinal procedures. Most patients are positioned by simply sitting up in their hospital bed, hanging their legs over the side of the bed, and leaning forward on a nurse or other assistant, who stands in front of the patient and allows the patient to lean on their shoulder. In the case of laboring pregnant patients, this support is frequently provided by an untrained family member. Most commonly the recommendation that the feet be supported on a stool is ignored.
Makeshift support methods and/or devices cause problems for the patient, for the support person, and for the anesthesiologist.
For the patient, the effect of makeshift support methods and devices is that patients are uncomfortable, unable to position themselves properly, and unable to prevent themselves from moving unpredictably. They are thereby unnecessarily exposed to the risks of discomfort and neurologic or other medically significant injury during the procedure.
When a support person is used to help position the patient, both the patient and the support person are at risk of injury.
A medically untrained support person may unexpectedly become unable to provide the required support during the procedure. This can lead to falls or other injuries to both the support person and the patient.
When a trained support person is used, this generally means that the patient's labor and delivery nurse is occupied with providing the required mechanical support, and therefore is distracted from other important duties such as ongoing continuous maternal and fetal monitoring, and also is unable to provide immediate treatment if an important medical event should occur.
For the anesthesiologist performing the procedure, makeshift support methods dictate that the procedure must be performed at a working height determined by the height of the support person, or if a stool is used to support the feet, by the height of the stool. These limitations force the anesthesiologist to work in an uncomfortable or awkward position, thereby making the procedure more difficult and hazardous than necessary.
To be useful in pregnant patients, a device should be compatible with the specific anatomy and needs of the laboring pregnant patient and her fetus. In labor, important, dangerous, and potentially fatal medical events may occur within seconds, as in the case of a maternal seizure during placement of a labor epidural, or minutes, as when fetal distress may be indicated by a deteriorating fetal heart rate tracing. Continuous and unencumbered access to the patient for the purposes of both fetal and maternal monitoring and possible emergency treatment should be assured at all times in order to avoid patient harm and consequent legal liability. Any device used to support a pregnant patient during any procedure is preferably also configured to allow it to be easily and rapidly disengaged to allow immediate re-positioning of the patient in to ‘normal’ labor and delivery posture on the standard labor and delivery bed.